Structural and conformational analysis of metal-containing peptides by one- and two-dimensional NMR spectroscopy. The case of thymulin.
Thymulin (formerly called FTS) is a well-defined nonapeptide hormone produced by thymic epithelial cells. Its biological activity and antigenicity depend on the presence of the metal zinc in the molecule. The interaction between this metal ion and thymulin has been investigated by means of one- and two-dimensional NMR experiments. These experiments were performed in dimethyl-d6 sulfoxide solution and in aqueous medium with different metal:peptide ratios. The results are compared with those obtained for complexes of thymulin with other metal ions (Cu2+ and Al3+) and for the [Ala4]- and [Ala8]-analogs in terms of biological activity. These comparative studies suggest that the 1:1 complex is the only conformation recognized by the antibodies. From the NOESY data, a spatial conformation has been proposed for this complex. This conformation should be the physiological one and could lead to a better insight into the conformation requirements at receptor sites.
Laussac
J P
JP
Laboratoire de Chimie de Coordination du CNRS, Toulouse, France.
D000595:Amino Acid Sequence; D004121:Dimethyl Sulfoxide; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008670:Metals / Q000737:chemistry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D012996:Solutions; D013935:Thymic Factor, Circulating / Q000737:chemistry*; D014867:Water; D015032:Zinc / Q000737:chemistry
D008670:Metals; D012996:Solutions; D014867:Water; D013935:Thymic Factor, Circulating; D015032:Zinc; D004121:Dimethyl Sulfoxide